Microelectronic devices are generally fabricated on semiconductor substrates as integrated circuits. A complementary metal-oxide-semiconductor (CMOS) field effect transistor (FET) is one of the core elements of the integrated circuits. Dimensions and operating voltages of CMOS transistors are continuously reduced, or scaled down, to obtain ever-higher performance and packaging density of the integrated circuits.
To further sustain this trend, novel nanostructures such as nanowires are explored as possible successors of the current state-of-art silicon devices.
However as nanowires are scaled down to smaller radii, the interaction of electrons with the surface of the nanowire become important and due to surface roughness of the nanowire this will become detrimental for the device performance due to mobility degradation.
As a result, surface roughness or high-k scattering becomes a dominant scattering mechanism that may depress the carrier mobility significantly, thus rendering nanowires useless for MOSFET operation.
As a conclusion, there is still a need for an improved FET design thereby avoiding surface interactions at the surface of the nanostructure.